Thursday, April 26, 2007

Until about 3,500 years ago, a spectacular ancient civilisation was flourishing in the Eastern Mediterranean. The ancient Minoans were building palaces, paved streets and sewers, while most Europeans were still living in primitive huts.

But around 1500BC the people who spawned the myths of the Minotaur and the Labyrinth abruptly disappeared. Now the mystery of their cataclysmic end may finally have been solved.

"The geo-archaeological deposits contain a number of distinct tsunami signatures," says Dutch-born geologist Professor Hendrik Bruins of the Ben-Gurion University of the Negev in Israel.

"The latter can only have been scooped up from the sea-bed by one mechanism - a powerful tsunami, dumping all these materials together in a destructive swoop," says Professor Bruins. The deposits are up to seven metres above sea level, well above the normal reach of storm waves.

"An event of ferocious force hit the coast of Crete and this wasn't just a Mediterranean storm," says Professor Bruins. Link

Sunday, April 22, 2007

Kant was a German philosopher, trained as a mathematician and physicist, who published his General History of Nature and theory of the Heavens in 1755. This physical view of the universe contained three anticipations of importance to astronomers;

Metaphysics explained by Robert Williams.

1. He made the nebula hypothesis ahead of Laplace.

2. He described the Milky Way as a lens-shaped collection of stars that represented only one of many "island universes," later shown by Herschel.

3. He suggested that friction from tides slowed the rotation of the earth, which was confirmed a century later. In 1770 he became a professor of mathematics, but turned to metaphysics and logic in 1797, the field in which he is best known. link

Thursday, April 19, 2007

A new "black smoker" -- an undersea mineral chimney emitting hot, iron-darkened water that attracts unusual marine life -- has been discovered at about 8,500 feet underwater by an expedition and dubbed the Medusa hydrothermal vent field.

The researchers picked that name to highlight the presence of a pink form of the jellyfish order Stauromedusae as well as numerous spiky tubeworm casings that festoon the vent chimney and bring to mind "the serpent-haired Medusa of Greek myth," said expedition leader Emily Klein.

"It's astonishing that a rich ecology thrives in these extreme environments," Klein added. She noted, however, that while all the organisms near vents are adapted to the high pressures at these depths, not all experience extremely high temperatures.

"The temperature of the ocean floor is about 2 C and there is a strong temperature gradient as you move away from the vent, so animals living a few inches away may experience temperatures only a few degrees above normal for the ocean floor."

"Despite the great tempeature of the vent water, it doesn't boil until 390 C because pressures on the ocean floor are so great, about 200 times the pressure at sea level," Klein said. The tremendous pressures result from the weight of almost two miles of seawater pressing down from above. link

Sunday, April 15, 2007

Scientists studied light absorbed and reflected by organisms on Earth, and determined that if astronomers were to look at the light given off by planets circling distant stars, they might predict thatsome planets have mostly non-green plants.

"We can identify the strongest candidate wavelengths of light for the dominant color of photosynthesis on another planet," said Nancy Kiang, lead author of the study.

On Earth, Kiang and colleagues surveyed light absorbed and reflected by plants and some bacteria during photosynthesis, a process by which plants use energy from sunlight to produce sugar. Organisms that live in different light environments absorb the light colors that are most available. For example, there is a type of bacteria that inhabit murky waters where there is little visible light, and so they use infrared radiation during photosynthesis.

According to scientists, the Sun has a specific distribution of colors of light, emitting more of some colors than others. Gases in Earth's air also filter sunlight, absorbing different colors. As a result, more red light particles reach Earth's surface than blue or green light particles, so plants use red light for photosynthesis. There is plenty of light for land plants, so they do not need to use extra green light. But not all stars have the same distribution of light colors as our Sun. Study scientists say they now realize that photosynthesis on extrasolar planets will not necessarily look the same as on Earth.

Wednesday, April 4, 2007

Armed with a computer video tracking system and an array of mathematical techniques researchers have revealed how the flight patterns of starved fruit flies constitute an optimal scale-free searching strategy – like the fractal patterns of a snowflake, a fly flight path appears similar whether viewed up close, or from a distance.

The researchers also found that searching is intermittent, such that flies actively search by making tight turns, and fly straight some distance to begin searching again. Scale-free movement patterns have been found in diverse animals including zooplankton, wandering albatrosses, jackals, and even human hunter-gathers. Intermittent searchers include octopi, graylings, and mating crickets.

Andy Reynolds says, "Our results with freely flying Drosophila appear to be the first reported example of searching behaviour that is both scale-free and intermittent. This suggests that these behaviours are not part of two different searching strategies, but rather represent a single very effective and perhaps widely adopted strategy." link

Monday, April 2, 2007

New research reveals that trends in popular culture (music, fashion, baby names) come and go at surprisingly regular and predictable rate, which is fueled by very few innovators amidst millions of people copying each other.

To come up with a template of the trend-setting machine, the scientists developed computer simulations based on a system of random copying in which hundreds or thousands of individuals copy each other with 2 percent or fewer being innovators. The model predicted regular and consistent turnover rates that matched the real-world data.

Bentley found that how quickly something comes into fashion and then fades out depends on the size of the list, with a top-100 list changing much faster than a top-40 list. However, the population number had no effect on turnover rate. The scientists suggest a larger population does mean more new ideas but it also means more competition for a top spot and they balance each other out.

Perhaps not surprisingly, the study also found that the more trendsetting innovators there are in a society, the faster one trend will replace another within a particular sector. “Innovators are the cool ones who ‘pump’ new fashions into our world,” Bentley said.